| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an inexpensive light emitting diode driving circuit that selectively drives two kinds of light emitting diodes emitting different colored light rays by using constant-current control integrated circuits or semiconductor switches of the number smaller than that of those used in the conventional example, and to provide apparatus using the driving circuit. <P>SOLUTION: The light emitting diode driving circuit is provided with a plurality of sets of two kinds of light emitting diodes LED1, LED2, LED<SB>n</SB>1, and LED<SB>n</SB>2 which are connected in parallel with each other and emit different colored light rays, a pair of power sources ES1 and ES2 which respectively energize the diodes LED1, LED2, LED<SB>n</SB>1, and LED<SB>n</SB>2, and a pair of semiconductor switches Q1 and Q2 which are connected in series with the two kinds of diodes to selectively connect the diodes to the power sources ES1 and ES2. The driving circuit is also provided with common constant-current generating sections IC1 and IC2 which are connected in series between the two kinds of light emitting diodes LED1, LED2, LED<SB>n</SB>1, and LED<SB>n</SB>2 and the pair of power sources ES1 and ES2 so as to generate constant currents from the currents flowing to the diodes LED1, LED2, LED<SB>n</SB>1, and LED<SB>n</SB>2. <P>COPYRIGHT: (C)2003,JPO</p> |
